<p>Octavio del Rio examines an ancient Maya skull, well-preserved in the low-oxygen environment of an underwater cave. The scene was captured by underwater photographer and explorer Wes C. Skiles, whose incredible images grace this gallery. Skiles <a href="http://blogs.nationalgeographic.com/blogs/news/chiefeditor/2010/07/national-geographic-photographer-wes-skiles-dies.html" target="_blank">died July 21</a> while filming and diving in the ocean off the Florida coast. His breathtaking coverage of blue holes is <i>National Geographic</i> magazine’s August <a href="http://ngm.nationalgeographic.com/2010/08/bahamas-caves/todhunter-text" target="_blank">cover story</a>.</p> <p>“Wes was a true explorer in every sense and a wonderful spirit,” Editor in Chief Chris Johns said. "He set a standard for underwater photography, cinematography, and exploration that is unsurpassed. It was an honor to work with him, and he will be deeply missed."</p> <p>Among many other endeavors, Skiles was a key part of the <a href="http://www.nationalgeographic.com/field/projects/blue-holes/" target="_blank">Blue Holes Project</a>.</p>